The Assessment for Sensitivity of a NO2 Gas Sensor with ZnGa2O4/ZnO Core-Shell Nanowires—a Novel Approach

Sensors

I-Cherng Chen²  Shiu-Shiung Lin⁵  Tsao-Jen Lin⁴  Cheng-Liang Hsu³  Ting Jen Hsueh¹ 

[1] National Nano Device Laboratories, Tainan 741, Taiwan;Micro Systems Technology Center, ITRI South, Industrial Technology Research Institute, Tainan 709, Taiwan;Department of Electronic Engineering National University of Tainan, Tainan, 700, Taiwan;Chemical Engineering Department, National Chung-Cheng University, Chia-Yi, 621, Taiwan;College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan

关键词: ZnGa₂O₄;    ZnO;    core shell;    nanowire;    NO₂;    gas sensor;    sensitivity;   

DOI  :  10.3390/s100403057

来源: mdpi

【 摘 要 】

The application of novel core-shell nanowires composed of ZnGa₂O₄/ZnO to improve the sensitivity of NO₂ gas sensors is demonstrated in this study. The growth of ZnGa₂O₄/ZnO core-shell nanowires is performed by reactive evaporation on patterned ZnO:Ga/SiO₂/Si templates at 600 °C. This is to form the homogeneous structure of the sensors investigated in this report to assess their sensitivity in terms of NO₂ detection. These novel NO₂ gas sensors were evaluated at working temperatures of 25 °C and at 250 °C, respectively. The result reveals the ZnGa₂O₄/ZnO core-shell nanowires present a good linear relationship (R² > 0.99) between sensitivity and NO₂ concentration at both working temperatures. These core-shell nanowire sensors also possess the highest response (<90 s) and recovery (<120 s) values with greater repeatability seen for NO₂ sensors at room temperature, unlike traditional sensors that only work effectively at much higher temperatures. The data in this study indicates the newly-developed ZnGa₂O₄/ZnO core-shell nanowire based sensors are highly promising for industrial applications.

【 授权许可】

CC BY   
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.